In various drilling operations it is desirable to locate adjacent wellbores. Examples of drilling operations which may require locating adjacent wellbores, include relief drilling, drilling U-shaped wells, and steam assisted gravity drainage (SAGD). From time to time wells blowout and it is desired to kill the well subsurface, thus it is necessary to accurately position the first well while drilling the second intercepting relief wellbore. Currently, a common application for locating adjacent wellbores occurs when drilling a second wellbore substantially parallel to a first wellbore such as in SAGD wells.
Current methods for locating casing (or drill string) of a first wellbore use wireline tools. Conducting locating surveys utilizing wireline tools, and relying on those results, has significant drawbacks. For example, using wireline equipment increases rig time and costs. Further, wellbore location information is only obtained periodically with these wireline methods. This unavailability to have constant, timely and accurate data can result in significant and costly errors.
Therefore, it is a desire to provide an adjacent well locating device and method that addresses drawbacks of the prior art locating devices and methods. It is a still further desire to provide an adjacent well locating device and method with measurement while drilling (“MWD”).